Turbine thrust control system

Patent metadata

Field	Value
Publication number	US-9341073-B2
Application number	US-201313962293-A
Country	US
Kind code	B2
Filing date	Aug 8, 2013
Priority date	Aug 8, 2013
Publication date	May 17, 2016
Grant date	May 17, 2016

Abstract

Systems and programs for controlling thrust in a turbine by adjusting the clearance between a packing seal and a rotating component are disclosed. In one embodiment, a system includes a controller configured to move a packing seal to a selected clearance position in response to a thrust pressure exceeding a target pressure, and a sensor coupled to the controller and configured to detect the thrust pressure.

First claim

What is claimed is:

1. A system for controlling thrust in a turbine, the system comprising:
a packing seal housed within a packing seal casing and positioned radially distal to a thrust fitting mounted circumferentially on a rotor of the turbine;
a controller communicatively coupled to the packing seal such that the controller is configured to move the packing seal to a selected clearance position in response to a thrust pressure against the rotor exceeding a target pressure; and
a sensor coupled to the controller and configured to detect the thrust pressure against the rotor.

2. The system for controlling thrust in a turbine of claim 1 , wherein the packing seal further includes a mechanical coupling component operatively connected to the controller.

3. The system for controlling thrust in a turbine of claim 1 , wherein the thrust fitting defines a step section within the turbine.

4. The system for controlling thrust in a turbine of claim 1 , wherein the thrust pressure comprises a first thrust pressure and a second thrust pressure, and the target pressure comprises a first target pressure and a second target pressure, wherein the controller is configured to move the packing seal to the selected clearance position in response to one of the first thrust pressure exceeding the first target pressure and the second thrust pressure exceeding the second target pressure.

5. The system for controlling thrust in a turbine of claim 1 , wherein the selected clearance position causes one of a net positive thrust and a net negative thrust against the thrust fitting, and the net positive thrust and the net negative thrust are within a maximum loading condition.

6. The system for controlling thrust in a turbine of claim 1 , wherein the packing seal is located at one of a low pressure-intermediate pressure junction, an intermediate pressure-high pressure junction, and a low pressure-high pressure junction.

7. The system for controlling thrust in a turbine of claim 1 , wherein the controller is further configured to move the packing seal to the selected clearance position in response to a pressure drop across the packing seal exceeding a target pressure drop.

8. The system for controlling thrust in a turbine of claim 1 , wherein the packing seal casing defines a first fluid flow area on a first side of the packing seal, and a second fluid flow area on a second side of the packing seal, the first fluid flow area being greater than the second fluid flow area.

9. The system for controlling thrust in a turbine of claim 1 , wherein the packing seal comprises one of a plurality of packing seals within the packing seal casing.

10. The system for controlling thrust in a turbine of claim 9 , wherein the selected clearance position comprises a plurality of selected clearance positions corresponding to each of the plurality of packing seals, and the system is further configured to move each of the plurality of packing seals to the corresponding one of the plurality of selected clearance positions.

11. A system for controlling thrust in a turbine, the system comprising:
a packing seal housed within a packing seal casing and positioned radially distal to a thrust fitting mounted circumferentially on a rotor of the turbine; and
a controller communicatively connected to the packing seal, wherein the controller moves the packing seal to a selected clearance position in response to one of the following:
a thrust pressure against the thrust fitting exceeding a target pressure; and
a pressure drop across the packing seal exceeding a target pressure drop;

wherein the selected clearance position causes one of a net positive thrust and a net negative thrust against the thrust fitting.

12. A program product stored on a non-transitory computer readable storage device, the program operative to control thrust in a turbine when executed, the non-transitory computer readable storage device being communicatively coupled to a packing seal housed within a packing seal casing and positioned radially distal to a thrust fitting mounted circumferentially on a rotor of the turbine, wherein the non-transitory computer readable storage device comprises program code for:
receiving a signal indicative of a thrust pressure against the thrust fitting;
calculating a difference between the thrust pressure and a target pressure,
determining a desired clearance position of the packing seal relative to the rotor based on a size of the difference between the thrust pressure and the target pressure; and
actuating the packing seal to move to the desired clearance position.

13. The program product of claim 12 , wherein the packing seal comprises one of a plurality of packing seals positioned radially distal to the thrust fitting.

14. The program product of claim 12 , further comprising program code for:
receiving a pressure drop value pertaining to a pressure drop across the packing seal; and
determining the desired clearance position based on both the difference between the thrust pressure and the target pressure, and the difference between the pressure drop value and the target pressure drop.

15. The program product of claim 14 , further comprising program code for calculating one of a difference between the thrust pressure and the target pressure, and a difference between the pressure drop value and the target pressure drop, wherein the determining includes determining the desired clearance position based on a size of the difference between the thrust pressure and the target pressure, and the difference between the pressure drop value and the target pressure drop.

Assignees

• Gen Electric

Inventors

• Donnelly Stephen Raymond

Classifications

• F01D3/04

  axial thrust being compensated by thrust-balancing dummy piston or the like · CPC title

• Y02E20/16

  Combined cycle power plant [CCPP], or combined cycle gas turbine [CCGT] · CPC title

• F01D11/025 Primary

  Seal clearance control; Floating assembly; Adaptation means to differential thermal dilatations · CPC title

• F05D2220/31

  in steam turbines · CPC title